CI: Maintenance

- Rename .travis dir to .ci, since it isn't just for Travis
- Convert Linux build scripts to posix sh
- Clean up some scripts per shellcheck

.ci/build-mac.sh

@@ -0,0 +1,27 @@
+#!/bin/sh -ex
+
+export CCACHE_SLOPPINESS=pch_defines,time_macros
+export CMAKE_PREFIX_PATH=/usr/local/opt/qt5/
+export PATH="/usr/local/opt/ccache/libexec:$PATH"
+
+# Setup vulkan and gfx-rs/portability
+curl -sLO https://github.com/gfx-rs/portability/releases/download/latest/gfx-portability-macos-latest.zip
+unzip -: gfx-portability-macos-latest.zip
+curl -sLO https://github.com/KhronosGroup/Vulkan-Headers/archive/sdk-1.1.106.0.zip
+unzip -: sdk-*.zip
+mkdir vulkan-sdk
+ln -s "${PWD}"/Vulkan-Headers*/include vulkan-sdk/include
+mkdir vulkan-sdk/lib
+cp target/release/libportability.dylib vulkan-sdk/lib/libVulkan.dylib
+# Let macdeployqt locate and install Vulkan library
+install_name_tool -id "${PWD}"/vulkan-sdk/lib/libVulkan.dylib vulkan-sdk/lib/libVulkan.dylib
+export VULKAN_SDK="${PWD}/vulkan-sdk"
+
+# Pull all the submodules except llvm
+# Note: Tried to use git submodule status, but it takes over 20 seconds
+# shellcheck disable=SC2046
+git submodule -q update --init $(awk '/path/ && !/llvm/ { print $3 }' .gitmodules)
+
+mkdir build && cd build || exit 1
+cmake .. -DWITH_LLVM=OFF -DUSE_NATIVE_INSTRUCTIONS=OFF -G Ninja
+ninja